php_switch command fails on macOS

[fvsch]

Apparently the syntax used for sed commands is specific to the GNU sed and fails for macOS’s built-in sed:

$ ./stack.sh php_switch
[?] Which PHP version do you want to use? 5.4, [5.6], 7 or 7.1:
sed: 1: "docker-compose.config.sh": extra characters at the end of d command
sed: 1: "docker-compose.config.sh": extra characters at the end of d command
Selected php56 as PHP version

(Despite the message, the docker-compose.config.sh is not updated.)

I was able to work around this issue by installing gnu-sed with Homebrew:

$ brew install gnu-sed --with-default-names